Title
Content of ibuprofen (assay)
Objective
To calculate the content of ibuprofen
Apparatus
Filter funnel , Filter paper , Beaker , Retort stand
, Conical flask , Dryer , Burette , Weighing boat
Materials
20 tablet of ibuprofen
Ethanol
Phenophthalein
0.1M sodium hydroxide
Procedure
:
1. 20
Ibuprofen tablets previously selected at random is weighed and powdered.
2. A
quantity of powder containing 0.5 g ibuprofen is extracted with 20 ml
chloroform for 15 minutes and is filtered through a sintered glass crucible (
BS Porosity No. 1)
3. The
residue is washed 3 times with 10ml chloroform and the combined filtrate is
gently evaporated just to dryness in a current of air. The residue is dissolved
in 100ml with ethanol (96%) previously neutralized to phenolphthalein solution.
4. The
solution is titrated with 0.1M sodium hydroxide to end point with
phenolphthalein solution as the indicator . The content of ibuprofen is
calculated if each ml of 0.1M sodium hydroxide is equivalent to 0.02063g of C13H18O2.
Result
and calculation
The weight of 20 tablets Ibuprofen in powder
form = 7.94g
Active ingredient of ibuprofen in each tablet = 0.5g
Active ingredient of ibuprofen in 20 tablets = 4.0 g
500 mg / 4000 mg
= Y / 7940 mg
Y = 992.5 mg
Titration of 0.1M sodium hydroxide = 15 ml
0.1M sodium hydroxide is equal to 0.02063 g of
Ibuprofen
15 ml x 0.02063 g = 0.30945 g
Percentage of deviation : [ (0.5 – 0.30945) x 100 ]
÷ 0.5 = 38.11 %
Discussion
The
amount of active ingredient in each Ibuprofen tablet is 0.5g which is
expected to be the final mass. However,
the calculated value is different from theoretical value which is 38.11 %
deviation ( 0.30945 g). The volume of NaOh of titration process is expected to
be aroun 24 mL for 0.5 g of Ibuprofen.
This
may be due to some errors occurred during the experiment.The solution are not
filtered properly using filter funnel and filter paper which then cause some of
the powder that are not dissolved in the chloroform will pass through into the
conical flask. In addition to that, the tablets used might be already
expired. So, the physicochemical
properties of Ibuprofen tablets might be affected.
Conclusion
In
conclusion, the content of Ibuprofen from the experiment is 0.30945 g which is
slightly different with theory, 0.5 g due to some errors.
References
1. https://en.wikipedia.org/wiki/Ibuprofen
2. Introduction
to Pharmaceutical Analysis, By Steen Hansen, Stig Pedersen-Bjergaard, Knut
Rasmussen
(https://books.google.com.my/books?id=S7S6a4OYTasC&lpg=PP1&pg=PP1#v=onepage&q&f=false
)
Questions
1. What are the objectives of the tests for
uniformity of diameter and uniformity of content ?
To ensure each tablet contain the amount of drug
substance intended with little variation among tablets within a batch. Then, to
indicate the individual contents are within limits set with reference to the
average content of the sample. Tablet diameter is a vital quality control test
for tablet packaging which affects packaging. Tablet thickness is determined by
the diameter of the tablet.
2. State the types of tablets and capsules that must
be tested for for uniformity of diameter and uniformity of content.
•
Effervescent Tablet
• Hard
and soft capsule
• Modified
Release Tablet/capsule
• Enteric-coated
tablet/capsule
• Uncoated
tablet
3. Give reasons for the non-compliance to test for
uniformity of weight.
It is because of the uneven feeding of granules into
the die. In other words, non-uniformity movement of the lower punch will result
in the variation in capacity of die space and have to carry out the test. If
the ingredients do not mix well at blending stage or do not weight the amount
of ingredients accurately, this will also produce those non-compliance.
4.Why does dissolution test suitable to be used for
batch to batch quality control?
It is as an
important part of product development and to obtain information on test batches
used in bioavailability/bioequivalence studies and pivotal clinical studies to
support specifications for quality control.
5.Describe other apparatus that you can use to
conduct dissolution test apart from the one found in the laboratory.
In United States Pharmacopeia (USP) General Chapter
<711> Dissolution, there are four dissolution apparatuses standardized
and specified.They are:
• USP Dissolution Apparatus 1 - Basket (37°C)
• USP Dissolution Apparatus 2 - Paddle (37°C)
• USP Dissolution Apparatus 3 - Reciprocating
Cylinder (37°C)
• USP Dissolution Apparatus 4 - Flow-Through Cell
(37°C)
USP Dissolution Apparatus 2 is the most widely used
apparatus among these four.
The performances of dissolution apparatuses are
highly dependent on hydrodynamics due to the nature of dissolution testing. The
designs of the dissolution apparatuses and the ways of operating dissolution
apparatuses have huge impacts on the hydrodynamics, thus the performances.
Hydrodynamic studies in dissolution apparatuses were carried out by researchers
over the past few years with both experimental methods and numerical modeling
such as Computational Fluid Dynamics(CFD).
